1. Field of the Invention
The present invention relates to an electronic component including a multilayer ceramic capacitor, and an interposer that mounts the multilayer ceramic capacitor onto a circuit board.
2. Description of the Related Art
Currently, chip components, in particular, miniature multilayer ceramic capacitors are frequently used for mobile terminals such as cellular phones. A multilayer ceramic capacitor includes a rectangular component body that functions as a capacitor, and outer electrodes formed at opposite ends of the component body.
In the related art, generally, as disclosed in Japanese Unexamined Patent Application Publication No. 8-55752, a multilayer ceramic capacitor is electrically and physically connected to a circuit board by placing outer electrodes directly on the mounting land of the circuit board of a mobile terminal, and bonding the mounting land and the outer electrodes together with a bonding agent such as a solder.
However, a multilayer ceramic capacitor is subject to mechanical distortion in some cases due to variations in the voltage applied to the multilayer ceramic capacitor. When this distortion occurs, the distortion is transmitted to the circuit board, causing the circuit board to vibrate. When the circuit board vibrates, vibration sound audible to the human ears occurs in some cases.
As a solution to this problem, for example, Japanese Unexamined Patent Application Publication No. 2004-134430 and Japanese Unexamined Patent Application Publication No. 2010-123614 describe not mounting the multilayer ceramic capacitor directly on the mounting land. In Japanese Unexamined Patent Application Publication No. 2004-134430, an interposer formed by an insulating substrate is used. In a case where an interposer is used, the multilayer ceramic capacitor is bonded to upper electrodes of the interposer, and lower electrodes of the interposer are bonded to mounting electrodes of the circuit board. The electrical continuity between each of the upper and lower electrodes is provided by a via-hole that penetrates the interposer. In Japanese Unexamined Patent Application Publication No. 2010-123614, the outer electrodes of the multilayer ceramic capacitor are held from both side end portions and supported in midair by a conductive support member, and the bottom surface of the conductive support member is bonded to a circuit board mounting electrode.
However, Japanese Unexamined Patent Application Publication No. 2004-134430 adopts a special structure in which the arrangement direction of the lower electrodes and the arrangement direction of the upper electrodes in the interposer cross each other, that is, the arrangement direction of the outer electrodes of the multilayer ceramic capacitor and the arrangement direction of the mounting electrodes with respect to the circuit board of the interposer cross each other. Therefore, in a case where vibration sound occurs when the multilayer ceramic capacitor is directly mounted onto the circuit board, changes to the land pattern or the like are required in the configuration according to Japanese Unexamined Patent Application Publication No. 2004-134430. However, such an improvement based on changes to the land pattern is difficult to achieve for circuit boards currently in use which typically require high-density mounting. Moreover, miniaturization is not easy to achieve, with the possibility of further increasing cost.
According to the configuration described in Japanese Unexamined Patent Application Publication No. 2010-123614, the multilayer ceramic capacitor is supported in midair by the conductive support member, which makes it difficult to achieve a reduction in height. In addition, it is difficult to mount the multilayer ceramic capacitor with an appropriate spacing between the multilayer ceramic capacitor and the circuit board. Further, because a flat-shaped conductor is used for the conductive support member, it is difficult to ensure sufficient mounting strength.